First Day Of Summer 2010: The Longest Day Of The Year (PHOTOS)

The first day of summer is today, June 21, 2010, also known as the summer solstice and the longest day of the year.

The sun will be shining throughout the day in the Northern Hemisphere, as summer solstice takes place due to the Earth tilting 23.5 degrees toward the sun.

This summer solstice, record-low Arctic ice has been a concern and solar energy has been a hot topic.

The Stonehenge ushered in summer solstice 2010 with more than 20,000 people. Vote on the most powerful photos from today's festivities below and feel free to share how you are celebrating the first day of summer in the comments.